There have been developed many bill handling machines such as vending machines, exchangers, automatic cash dispensers, automatic teller machines and bill validators mounted in gaming machines. Sometimes, these bill handling machines may encounter an illegal action by an imprudent person who fraudulently tries to extract a bill from inside of the machine by pulling out a string connected to the bill already received within the machine as a genuine one. To inhibit such a fraudulent action, some of these machines have an anti-pullback unit for preventing the bill from being taken out of the machine with any extracting tool.
U.S. 2006/284410A1 discloses a bill processing device which comprises a plurality of long channels disposed on a convexly bent path surface to form a bill path along a conveying direction of a bill and in parallel relation to each other in a transverse direction of the bill path, and a row of projections extending from respective side walls of the long channels. Each projection has a first surface inclined to a bottom surface side of the long channel to guide a foreign matter such as string or band conveyed with the bill to enter the long channel, and a second surface horizontal or inclined to the bottom surface side of the channel to inhibit string which has entered the long channel from exiting from the long channel. When string is connected to conveyed bill, it naturally enters long channel away from side wall to radially inward move along the first surface of the projection. Then, the string further goes into a recessed hole adjacent to the projection to effectively hinder escape of string from the recessed hole.
However, the disclosed bill processing device has a drawback in that disadvantageously it only has a single row of the stationary and irrotational projections not to wind or tangle string or band connected to the conveyed bill around projection and a bottom surface of the long channel. Accordingly, the prior art bill processing device would involve a large risk of inconvenient extraction of bill by drawing the string connected to bill.
Therefore, an object of the present invention is to provide a rotary anti-pullback unit of fletched fins for preventing extraction of a valuable document already received or stacked within an associated device by pulling out an extracting tool connected to the document. Another object of the present invention is to provide a rotary anti-pullback unit of fletched fins provided with a rotatable rotor capable of reeling an extracting tool connected to a document around the rotor to inhibit fraudulent extraction of the document.